1881.] 



MICKOSCOPICAL JOUENAL. 



229 



Lake, about thirty miles from Easton. 

 They were obtained from an old oak 

 trunk and from the bark of an old 

 pine stump, in the latter of which 

 they are most frequently found. I 

 searched in vain for them, last year, 

 in the woods in the vicinity of Easton, 

 although it is possible they may yet 

 be found there. In 1877 Dr. Leidy first 

 observed these parasites, and a brief 

 notice of them was published. Three 

 or four varieties of these remarkable 

 protozoans are enumerated by him, but 

 he adds : " There may be some forms 

 that are merely younger stages of the 

 same species." 



The most conspicuous and extra- 

 ordinary of the parasites has been 

 named TricJionympha agilis ; and, 

 notwithstanding all his study, Dr. 

 Leidy declares his inability to deter- 

 mine its character sufficiently to 

 decide whether it should be regarded 

 as a ciliated infusorian, a gregarine, 

 or a rhabdocoelus turbellarian ; but 

 he is disposed to regard it as the for- 

 mer, or rather as of intermediate char- 

 acter between the first two. There 

 appears to be something like food in 

 the centre of many of them, but Dr. 

 Leidy says he has watched for hours 

 myriads of individuals, without ever 

 seeing one of them swallow or 

 discharge a particle of food. My own 

 limited experience corresponds with 

 this statement. Thus far no contract- 

 ing vesicle has been observed. I do 

 not pretend to give an elaborate de- 

 scription of the head, body, cilia, 

 etc., time will not permit. Among 

 the more beautiful varieties, he class- 

 es also the Pyrsonympha, which may 

 be distinguished by its zigzag, undul- 

 ating movement, and the wavy move- 

 ment of its cils. A large nucleus is 

 present in Pyrsonympha, it is oval or 

 round, and often appears ovoid or 

 pyriform. This animal is classed as 

 a ciliated infusorian. 



Another of the parasitic communi- 

 ty is known by the title of Dinenym- 

 pha, or whirling nymph, a ciliated 

 infusorian, probably related to 

 the familiar genus Opalina, though, 



unlike this and like its associates, it 

 appears to swallow food ; its body 

 contains variable proportions of 

 coarse granules. Dinenympha is an 

 active creature, incessantly in motion, 

 though, like its associates, remains 

 nearly stationary in some positions, it 

 always appears twisted and of some- 

 what spiral form. It is closely in- 

 vested with short, rapidly vibrating 

 cils. 



Time will not allow me to describe 

 this numerous but beautiful family ; 

 I barely enumerate a few more 

 by name. 



Iracis Migrans. This animal cor- 

 responds to one of the same name 

 inhabiting the proboscis of the house- 

 fly. A gregarine has also been no- 

 ticed in the Termite. Vibrios occur 

 also in great numbers, ^throniitus 

 was the name originally given to a 

 genus of delicate filamentous plants 

 found in the intestines of certain 

 myriapods, Spirobolus Marginatus, 

 and of the coleopterous insect, Pas- 

 salus corfiutus. Careful examination 

 proves this plant to be the same, and 

 as if to fill up the measure of life ca- 

 pable of being sustained by the ter- 

 mite, it is infested with a mite — a 

 species of Gamasus. 



Termites, as Leidy well observes, 

 are so common and easily obtained 

 in many neighborhoods, they will, no 

 doubt, become favorite subjects to 

 illustrate the infinity of life and the 

 wonders of the microscope. 

 o 



A ?Jew Cement. 



BY PROF. C. B. PARKER, M. D. 



I desire, through your excellent 

 columns, to call the attention of your 

 readers to a preparation for perma- 

 nently sealing and finishing glycerin- 

 mounts, presented, I believe, for the 

 first time to American microscopists. 

 All admit the desirability of glycerin- 

 mounts, and, indeed, the impractica- 

 bility of preserving certain objects in 

 any other way ; yet, if my experience 

 corresponds with that of others, I 

 have often had to mourn the destruc- 



